The present invention relates to radio frequency (RF) power amplifiers (PA) module. Portable devices such as laptop personal computers, Personal Digital Assistant and cellular phones with wireless communication capability are being developed in ever decreasing size for convenience of use. Correspondingly, the electrical components thereof must also decrease in size while still providing effective radio transmission performance. However, the substantially high transmission power associated with RF communication increases the difficulty of miniaturization of the transmission components.
One important requirement for the state-of-the-art wireless devices is to provide power amplification in a plurality of frequency bands and a plurality of communication standards with different digital modulation method. The quality and power level of the amplified RF signals need to be properly controlled. For example, for high data rate wireless applications, the output signals is required to be linear over a wide signal power range in each of the plurality of frequency bands. Preferably the amplification is reduced or increased according to input RF signal, transmittance range and data rate so that power consumption can be optimized.
Wireless communication devices are also used to receive and transmit signals under different standards, protocols and frequency bands. Various standards and protocols can specify a wide range of wireless applications spanning from mobile devices, information technologies to consumer electronics. Providing users wireless communication capabilities under different standards, protocols and frequency bands has been a challenge to the wireless equipment and in particular RF power amplifiers.
A constant challenge to the manufacturing of wireless communication devices is to increase yield and reduce product loss. The yields of wireless communication devices are affected by the performance of its key components such as base band processor, RF transceiver, and power amplifier. The costs and manufacture cycle are significantly influenced by the manufacture yield.